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The grooves decrease in depth from one end of the block to the other, according to a scale stamped next to them. A typical Hegman gauge is 170mm by 65mm by 15mm, with a channel of grooves running lengthwise, 12.5mm across and narrowing uniformly in depth from 100 μm to zero and used to determine particle size .
In particular, air permeability is almost universally used in the cement industry as a gauge of product fineness which is directly related to such properties as speed of setting and rate of strength development. Other fields where air permeability has been used to determine specific surface area include: Paint and pigments; Pharmaceuticals
Test methods for the water-cement ratio and fineness modulus). 1919 – Effect of Curing Condition on Wear and Strength of Concrete (Describing 120 tests on cylinder-shaped samples and 300 tests on cubic samples in various moisture conditions and testing periods varying from 3 days to 4 months).
The same value of fineness modulus may therefore be obtained from several different particle size distributions. In general, however, a smaller value indicates a finer aggregate. Fine aggregates range from an FM of 2.00 to 4.00, and coarse aggregates smaller than 38.1 mm range from 6.75 to 8.00.
A sieve analysis (or gradation test) is a practice or procedure used in geology, civil engineering, [1] and chemical engineering [2] to assess the particle size distribution (also called gradation) of a granular material by allowing the material to pass through a series of sieves of progressively smaller mesh size and weighing the amount of material that is stopped by each sieve as a fraction ...
A cover meter is an instrument to locate rebars and measure the exact concrete cover. Rebar detectors are less sophisticated devices that can only locate metallic objects below the surface. Due to the cost-effective design, the pulse-induction method is one of the most commonly used solutions. [1]
The test reports loss of mass to abrasion and impact, expressed as a percentage of initial sample mass. [7] Maximum acceptable loss for the base course of the road is 45%; the more demanding surface course must be 35% or less. [1] The test was developed by the city engineers of Los Angeles in the 1920s. [8]
More water is therefore used than is chemically and physically necessary to react with cement. Water–cement ratios in the range of 0.40 to 0.60 are typically used. For higher-strength concrete, lower w/c ratios are necessary, along with a plasticizer to increase flowability.